1. Field of the Invention
The present invention generally relates to a package structure, and particularly to a light-emitting diode package structure.
2. Description of Related Art
The light-emitting diode has the advantages including low power consumption, long device lifetime, no idling time and fast response speed. Besides, the LED has the features of small dimension, great resistance to vibration, capability for mass production and easily to be adapted to the ultra-small or array device under demand so that the LED is widely used on the indicator or display device of the information appliance, the telecommunication appliance and the consumptive electronic appliances and has become indispensable electronic gadgets in our daily life.
The LED chip should be packed before being used. Besides enhancing the light extraction efficiency, the current package technology focuses on decreasing the thermal stress of the package structure to increase the lifetime and the reliability of the package structure.
FIG. 1 is a schematic cross-sectional view showing a conventional LED package structure. As shown in FIG. 1, the conventional LED package structure 100 has a leadframe 110, a LED chip 120, a wire 130, a housing 140 and an encapsulant 150, wherein the housing 140 wraps the leadframe 110 and has a recess R. The bottom of the recess R has two openings 142 and 144 exposing a portion of the leadframe 110, wherein the housing 140 possesses a spacer 146 for separating the openings 142 and 144 apart and the spacer 146 protrudes from the leadframe 110 at a surface 112 facing toward the recess R. The LED chip 120 is disposed on the surface 112 of the leadframe 110 in the opening 142 and the wire 130 is connected the LED chip 120 with the leadframe 110 exposed by the opening 144. The molding compound 150 is disposed in the recess R to cover the LED chip 120 and the wire 130.
During the wire bonding process, the wire 130 is connected to the LED chip 120 by the bonding tip B, and then the bonding tip B pulls the wire 130 and moves along a wire bonding path A so as to connect the wire 130 to the leadframe 110 exposed by the opening 144. However, during the movement of the bonding tip B, it is easy for the bonding tip B to hit the spacer 146 protruding from the surface 112, which leads to the bonding failure. Therefore, the design of the housing 140 leads to the raising of the difficulty of the wire bonding and the increasing of the fabricating cost.